Articulated leg brace



\ Oct. 3, 1939. F. A. DRESSER ARTICULATED LEG BRACE Filed April 15. 1936 Patented Oct. 3, 1939 UNITED FFi E Application April 13,

7 Claims.

This invention relates to braces, more particularly to an improved type of articulated leg brace.

While many different types of articulated leg 5 braces have been suggested, these present certain disadvantages, particularly with respect tothe placement and operation of the locking means. For the most part such locking means have been constructed to function directly on the aligned braces and closely adjacent the pivot. Such locking means were therefore of rather bulky and heavy construction. Similarly, due to the fact that the locking means were directly associated with the braces at the knee pivot, a portion of such means and/or the unlatching mechanism projected rearwardly, thus detracting from the comfort of the wearer.

I have found that a brace presenting greater rigidity and durability combined with increased 20 comfort and operative convenience for the wearer can be constructed by utilizing a novel type of locking device and effectively associating this with certain structural parts of the members so that the metallic units of the construction are all positioned in the front part of the brace. This position insures greater comfort since, when sitting, no metal parts are under the leg of the wearer. Such placement of the parts also, as will be seen hereinafter, insures greater convenience in operating the latching mechanism.

An object of the present invention, therefore, is to provide a novel type of articulated leg brace.

Another object is to provide an improved locking device for articulated leg braces.

With these and other equally important and related objects in view, the invention comprehends the concept of utilizing a special type of bracing member and associating this effectively with a novel locking mechanism whereby a light, comfortable, rigid leg brace is insured.

To enable a more ready comprehension of the invention a preferred physical embodiment is shown in the accompanying drawing, in which:

Figure 1 is a side elevation of the structure.

Fig. 2 is a front view of the structure adja cent the joint. I

Fig. 3 is a section taken on line 3-3 of Fig. 2.

Fig. 4 is a section taken on line fi--fi of Fig. 2. As shown in the drawing, the brace structure includes the lower pair of brace struts I and 2 which are pivotally connected respectively to the upper brace struts 3 and 4. The strut 2, as shown, is bowed outwardly as at 5 on a brace intended for the left knee to insure adequate 1936, Serial N0. 74,212

accommodation for the knee.

right leg would be correspondingly conformed.

As shown in Fig. 1, the struts l and 3 are pivotally connected at 6. In order to insure a strong structure at this point of articulation the strut I is formed with an offset apertured end and the strut 2 is similarly formed with an offset apertured portion contiguous the terminus of strut I. The struts and 2 are so mounted, as will be understood, that the apertures are in alignment to receive the pivot pin 6. The strut I is further provided with the plates I (one on each side of the strut) which are riveted or otherwise rigidly secured thereto. The upper strut or brace member 3 is likewise provided with the plate 8 which projects between the adjacent plate I and the reduced apertured bearing extension on strut i. The pivot pin thus projects through the aligned apertures of the plates I and 8 and the bearing extensions of struts l and 3 to give a rugged and lateral rigid joint. A similar joint, as will be understood, is established between the strut members 2 and i.

The strut members I, 2, 3 and 4 may be fabricated of any suitable material, such as light weight, high strength aluminum or magnesium alloys, stainless steel tubular members and the like.

As shown particularly in Fig. 1, the lower portion of the brace comprising the strut members I and 2 is extended downwardly and is provided at the lower portion with the pivotally connected plate, member Ii] which is adapted in the typical manner to be attached to a shoe. The connection between the strut members I and 2 and the heel plate In is detachable so that the members may be removed from the plate. As described hereinbefore, the present brace is so con-' structed that the locking mechanism is positioned in the front part of the brace and in a readily accessible position. Furthermore the locking mechanism is of novel construction and is particularly characterized by the fact that the lock itself is a combined spring and tension lock.

As shown in Figs. 2 and 3, at a predetermined distance below the knee joint the braces I and 2 are provided with the metal plates II. These are rigidly secured to the struts by any suitable means, such as rivets I2. Attached to the inner portion of plate II is a second plate l3 which is formed with a vertical extension it. This vertical extension is projected laterally, as at I5 (see Fig. 2), to form a U-shaped slot. As will be seen more fully hereinafter, the plates II and I3 combine with the resilient strut member 20 The brace for the to effectively lock the upper and lower pairs of struts in alignment.

The member 20, which preferably is a large gauge resilient steel wire, is constructed in the form of a bail or arc having the laterally projecting ends 2|. These ends project through the aligned apertures in plates H and i3. As will be seen from an inspection of Figs. 2 and 3, the sides of the member 20 are adapted to contact the U-shaped abutments I4 at a point displaced from the pivotal point 2|. Due to the shape of the abutments [4 these in effect provide a slot in which the locking member may be moved. Thus locking member 20 may be pivoted from a position substantially parallel to the struts l and 2 to a position, determined by the length of the lateral projection I5, which is angular to the struts.

The upper or are portion of the member 26 is adapted to resiliently slide over and positively engage a member attached to the upper pair of struts so as to lock the two pairs of struts in vertically aligned position.

It is particularly to be observed, as will be seen in Fig. L'that the locking member 20 engages itself in cooperating locking members at a point displaced some considerable distance laterally of and vertically above the pivot or articulation point 6 so that the locking members in fact form a rigid tension truss unit when in locking position. This, as will be appreciated, is in sharp contradistinction to prior art structures in which the locking means operated directly in the vertical plane of the brace struts. Likewise it will be understood that since the major locking stresses here are taken substantially under tension rather than in bending moments, a much simpler and lighter construction may be utilized.

With the concept as expressed above in view it will be appreciated that it may be effectuated by a number of different specific types of mechanisms. That shown in the drawing operates most effectively and is preferred, although it will be understood that it is susceptible of rather wide modification.

As noted above, the locking point for the locking engagement of member 20 is preferably positioned forwardly of and above the pivot point 5. This position is attained and additional advantages secured by utilizing the arcuate plate 33. This member, formed of relatively heavy gauge metal, is rigidly attached to the upper struts 3 and 4 and preferably is riveted thereto. It com-' prises a semi-cylindrical member of relatively great depth and functions to rigidly secure the two upper struts together. By constructing this of relatively heavy material and of some considerable depth, the upper struts may be securely attached without the necessity of utilizing any ad'- ditional metallic bracing members in the rear portion of the strut. This is to say that in the brace constructed according to the present invention, there are no metallic parts in contact with the rear portion of the leg to cause discomfort, impede circulation, and the like.

As shown particularly in Figs. 2 and 3, the plate 30 has attached thereto a downwardly extending member 3|. Attached to such member is a second arcuate metal member 32 which projects downwardly and laterally and near its outer end is riveted or otherwise rigidly secured to the plate member 33. This plate member is in turn riveted to the lower portion of the upper brace strut 3. The plate member 33 has a lower portion in alignment with the joint and this portion is apertured to receive the pivot 6, thus further strengthening and rigidifying the joint.

Th plate members 3i and 32 are secured together by means of the rivet 40. As shown in Fig. 4, this projects through the plates 3! and 32 and pivotally mounts the novel unlatching lever 53. This lever, as more particularly shown in Fig. 4, is provided with an operating handle 5! and is generally curved or arcuate in form to conform generally to the contour of the plate 32. As will be noted particularly in Fig. 4, the stud or rivet 48 connects the plates 3! and 32 and forms a pivot for the pivotal movement of the locking lever 50. The stud 40 is enlarged on the outer surface, as shown particularly at 4!. This enlarged stud portion fill is in effect a locking stud and is adapted to receive the member 20 in looking engagement. For this purpose the upper peripheral portion of the stud, see Fig. 3 particular- 1y, is made concave, at 32, to receive the member 20 in nested engagement. The stud member 40 likewise performs another function. As will be noted from an inspection of Fig. 3, the lower portion of stud 4! is formed with the cam surface 13.

Assuming that the brace is in the unlocked posiof struts i and 2 the member 20 rides upon the curved surface of plate 32 and is forced outward- 1y into the slot lock M. The structure is so designed that at the time the sides of the locking member 29 contact the bottom of the slot Hi the curved upper portion of the member 20 is at the base of the stud l.

Further pivotal movement of the struts about the pivot point 6 causes theupper portion of member 20 to ride up on the cam surface 43. During this movement the member 2! is flexed or bent, such flexing being permitted by the resiliency of the material of which the member 23 is constructed. Further pivotal movement of the struts about the pivot point will cause the upper arc portion of member 2a to slide over the flat face of the stud 52. When the relative pivotal move ment of the upper and lower pair of struts is continued to the point where they come into vertical alignment, the now flexed or stressed member 26 snaps resiliently into the groove 42 and thus forms, with members 32, 3! and 33, a rigid trussed frame. In this position of the parts rearward pivotal movement of the upper pair of struts with respect to the lower pair of struts is positively prevented due to the fact that such movement is resisted by the locking member 20 now acting under tension. Forward movement of the upper pair of struts with respect to the lower pair of struts is prevented and resisted first by the abutment of the contiguous portion of struts I and 3 on the one hand and struts 2 and l on the other, as well as by the resistance imposed by the member 23 acting against the plate 3i. It is particularly to be observed that this rigid effective locking structure is achieved without the utilization of any metallic members extending between the struts on the back portion of the leg.

The parts just described, particularly members 3i and 32, also function in the unlocking operation. As has been described, the stud 4| serves F as a point of pivotal support for the unlatching lever 50. This member 50 is formed with a cam surface, as for example a conical stud 63 which is positioned laterally of the stud 40. When it is desired to unlatch the now rigid members, the

rear of the leg of the wearer.

lever arm 50 is moved upwardly. During this movement it pivots about the stud ll and the resilient member 20 rides up on the conical orother cam surface 60. structed of such a height that when the member 20 rides up on the highest point, such member clears the edge of the stud M. In other words, the operation of the lever 58 with its cam forces the resilient locking member 28 up out of the groove 42 and over the lip of the stud. The brace, being thus unlatched, may be pivoted to any desired degree about the pivot point 6. The arcuate form of the operating lever 58 provides a neat construction. This is to say the mechanism is so designed that the unlatching lever is not obviously apparent through the clothes of the wearer.

In the manner well understood by those skilled in the art, the brace is provided with leather bands and pads to permit attachment of the brace on the leg. Thus the upper portion of the brace may be provided with a wide thigh band E0. This band may be provided with a metal slot or thimble H, or other means, in which the upper end of strut 3 is detachably mounted. The opposite side of the band 10 is securely attached to the inner strut 4 in any suitable manner. Similarly a leather or other pliable attachment band I2 is provided just above the knee. Preferably this band is riveted to the struts and provides a soft padding between the metal plate 36 and the leg. The band 72 may be provided with the straps l3 and the buckles or'other attaching means M in the usual manner. In the preferred form of construction also a knee pad I5 is provided. This is attached at one side adjacent the pivot point and extends across and may be attached, as by means of the strap 16, to the opposite strut 3. This latter pad is thus interposed between the leg of the wearer and the metal locking members 3!, 32 and 50. Similarly, another pad is provided below the knee joint. Such pad 80 is preferably riveted to one strut and is detachably secured, as by means of the strap 8!, to the opposite strut. This pad, as will be appreciated, serves to prevent contact of the leg with the resilient locking yoke 20.

It will now be appreciated that the brace structure herein described presents many advantages. The member is quite light in view of the fact first that the maximum strength and bracing effect is secured with the minimum of structural elements; the lightness of the bracing structure is permitted and accentuated by the fact that the major locking stresses are taken under tension. The lightness of the structure can further be increased by utilizing a light weight, high strength alloy in the construction.

It is particularly to be observed, as has been pointed out hereinbefore and as is quite apparent from an inspection of Fig. 1, that a brace constructed in accordance with the present invention presents no metallic members in the The convenience resulting from this is, on the other hand, not achieved at the expense of structural strength; on the contrary the brace construction as described herein is eminently rigid and durable.

It will also be appreciated that by utilizing a resilient member 20 as part of the locking mechanism and by having this cooperate with the upper strut members 3 and 4 at a point displaced laterally from and vertically above the pivot 6, an ideal truss type of construction is insured. This is in sharp contradistinction to prior art The cam surface Gil is con as bending moments.

Therefore, while the preferred modification of the invention has been described as shown, it is to be understood that this is given to exemplify' the. broad principles of construction involved and not as limiting the invention to any specific design of brace.

I claim:

1. In a leg brace of the character described, a lower pair of brace struts, an upper pair of brace struts, means to pivotally connect the struts and means to lock the said pairs in vertically aligned position, said means including an are shaped resilient member pivotally connected to one pair of struts and detachably engageable with the other pair of struts, such being operated under tension to maintain the struts in aligned locked position.

2. In a leg brace comprising an upper pair of parallel brace struts and a lower pair of brace struts pivotally connected to the said upper pair, a semi-circular rigid plate interconnecting the upper brace struts and provided with a locking member, a hoop-shaped resilient member pivotally connected to the lower brace struts and adapted for locking engagement with the said locking member, and means mounted on said plate for unlocking said resilient member.

3. In a leg brace of the character described including an upper pair of struts and a lower pair of struts pivotally connected respectively to the upper struts, means to lock the said pairs in vertically aligned position comprising a resilient loop member pivotally connected to the struts of the said lower pair at a point displaced considerably below the pivot point and means interconnecting the upper pair of struts and adapted to cooperate with the said loop to lock member of the upper pair of struts, a resilient loop pivotally connected to each member of the lower pair of struts, a locking stud associated with the said plate and adapted to resiliently receive the said loop, and means pivotally associated with the said plate and adapted upon operation to unlock the said loop.

5. In a leg brace of the character described, an upper pair of brace struts, a lower pair of brace struts, the contiguous members of each pair being pivotally connected to form an articulated leg brace, an arcuate metal plate rigidly attached to the struts on the upper pair and extending across said struts in the front portion, a locking stud associated with said plate, a lever having a cam surface thereon pivotally associated with said plate; a resilient wire loop pivotally connected to each of the lower struts and having its loop portion resiliently engageable with the staid stud for locking engagement and engageable with the said cam for unlocking engagement.

6. In a leg brace an upper pair of brace struts, a lower pair of. brace struts, pivots interconnecting the contiguous struts of each pair, an arcuate rigid plate secured to each strut of the upper pair, and means to lock the upper and lower pairsofstruts in vertically aligned position comprising a member pivotally connected to each oneof the lower struts and resiliently and detachably engaging the plate; the said aligned struts, arcuate plate and pivotally connected member forming a truss construction in which the-pivotally connected member acts under tension during locking engagement and a member pivotally mounted on the plate and adapted to disengage the locking member from the plate.

7. In a leg brace of the character described, an upper pair of brace struts, a lower pair of brace struts, the contiguous members of each pair being pivotally connected to form an ar- 

